Buggy code:
public boolean isVersioned ( ) { } public boolean isVisible ( ) { } public final boolean isVisibleInHierarchy ( ) { } public final void markRendering ( ) { } public final void modelChanged ( ) { } public final void modelChanging ( ) { } public final Page newPage ( final Class < ? extends Page > c ) { } public final Page newPage ( final Class < ? extends Page > c , final PageParameters parameters ) { } public final void prepareForRender ( ) { } public final void redirectToInterceptPage ( final Page page ) { } public final void remove ( ) { } public Component < T > remove ( final IBehavior behavior ) { } private boolean removeBehavior ( final IBehavior behavior ) { } public final void render ( ) { } public final void render ( final MarkupStream markupStream ) { } public final void renderComponent ( ) { } public final void renderComponent ( final MarkupStream markupStream ) { } public final void rendered ( ) { } public void renderHead ( final HtmlHeaderContainer container ) { } public void replaceWith ( Component < ? > replacement ) { } public final boolean sameInnermostModel ( final Component < ? > component ) { } public final boolean sameInnermostModel ( final IModel < ? > model ) { } public final Component < T > setComponentBorder ( final IComponentBorder border ) { } public final Component < T > setEnabled ( final boolean enabled ) { } public final Component < T > setEscapeModelStrings ( final boolean escapeMarkup ) { } final void setMarkupIdImpl ( Object markupId ) { } public void setMarkupId ( String markupId ) { } public final < M > void setMetaData ( final MetaDataKey < M > key , final M object ) { } public Component < T > setModel ( final IModel < T > model ) { } @ SuppressWarnings ( "unchecked" ) IModel < T > getModelImpl ( ) { } void setModelImpl ( IModel < T > model ) { } public final Component < T > setModelObject ( final T object ) { } public final Component < T > setOutputMarkupId ( final boolean output ) { } public final Component < T > setOutputMarkupPlaceholderTag ( final boolean outputTag ) { } public final void setRedirect ( final boolean redirect ) { } public final Component < T > setRenderBodyOnly ( final boolean renderTag ) { } public final void setResponsePage ( final Class < ? extends Page > cls ) { } public final void setResponsePage ( final Class < ? extends Page > cls , PageParameters parameters ) { } public final void setResponsePage ( final Page page ) { } public Component < T > setVersioned ( boolean versioned ) { } public final Component < T > setVisible ( final boolean visible ) { } @ Override public String toString ( ) { } public String toString ( final boolean detailed ) { } public final CharSequence urlFor ( final Class < ? extends Page > pageClass , final PageParameters parameters ) { } public final CharSequence urlFor ( final IBehavior behaviour , final RequestListenerInterface listener ) { } public final CharSequence urlFor ( final IPageMap pageMap , final Class < ? extends Page > pageClass , final PageParameters parameters ) { } public final CharSequence urlFor ( final IRequestTarget requestTarget ) { } public final CharSequence urlFor ( final RequestListenerInterface listener ) { } public final CharSequence urlFor ( final ResourceReference resourceReference ) { } public final Object visitParents ( final Class < ? extends MarkupContainer < ? > > c , final Component . IVisitor < Component < ? > > visitor ) { } public final void warn ( final String message ) { } private void notifyBehaviorsComponentBeforeRender ( ) { } private void notifyBehaviorsComponentRendered ( ) { } protected final void addStateChange ( final Change change ) { } protected final void checkComponentTag ( final ComponentTag tag , final String name ) { } protected final void checkComponentTagAttribute ( final ComponentTag tag , final String key , final String value ) { } protected void checkHierarchyChange ( final Component < ? > component ) { if ( ( ! ( component . isAuto ( ) ) ) && ( getFlag ( Component . FLAG_RENDERING ) ) ) { <START_BUG> throw new WicketRuntimeException ( "Cannot<seq2seq4repair_space>modify<seq2seq4repair_space>component<seq2seq4repair_space>hierarchy<seq2seq4repair_space>during<seq2seq4repair_space>render<seq2seq4repair_space>phase" ) ; <END_BUG> } } protected void detachModel ( ) { } protected final String exceptionMessage ( final String message ) { } protected MarkupStream findMarkupStream ( ) { } protected final Page findPage ( ) { } protected List < IBehavior > getBehaviors ( Class < ? extends IBehavior > type ) { } protected final boolean getFlag ( final int flag ) { } protected final boolean getFlag ( final short flag ) { } protected final IModel < ? > getInnermostModel ( final IModel < ? > model ) { } protected IModelComparator < T > getModelComparator ( ) { } protected boolean getStatelessHint ( ) { } @ SuppressWarnings ( "unchecked" ) protected IModel < T > initModel ( ) { } protected final void internalOnAttach ( ) { } protected final void internalOnDetach ( ) { } protected void internalOnModelChanged ( ) { } protected final void markAttached ( boolean attached ) { } protected final boolean isAttached ( ) { } protected boolean isBehaviorAccepted ( final IBehavior behavior ) { } protected final boolean isIgnoreAttributeModifier ( ) { } protected MarkupStream locateMarkupStream ( ) { } protected void onAfterRender ( ) { } @ Deprecated protected final void onAttach ( ) { } protected void onBeforeRender ( ) { } protected boolean callOnBeforeRenderIfNotVisible ( ) { } @ Deprecated protected final void onBeginRequest ( ) { } protected void onComponentTag ( final ComponentTag tag ) { } protected void onComponentTagBody ( final MarkupStream markupStream , final ComponentTag openTag ) { }

Fix:
throw new WicketRuntimeException ( "Cannot<seq2seq4repair_space>modify<seq2seq4repair_space>component<seq2seq4repair_space>hierarchy<seq2seq4repair_space>after<seq2seq4repair_space>render<seq2seq4repair_space>phase<seq2seq4repair_space>has<seq2seq4repair_space>started<seq2seq4repair_space>(page<seq2seq4repair_space>version<seq2seq4repair_space>cant<seq2seq4repair_space>change<seq2seq4repair_space>then<seq2seq4repair_space>anymore)" ) ;